A system for aligning a weapon to a high-performance target sensor. A reference measurement sensor installed on the target sensor measures the direction and range to each of several references points on the weapon. From these measurements, and measurement by the target sensor of target states, a processing circuit calculates the states of the target in a coordinate system of the weapon. Each reference point may be a retroreflector; the reference measurement sensor may include an imaging sensor to measure direction, and a laser range finder to measure range.